A Good Diamond

A good diamond with its high degree of brilliance and fire, as well as extreme hardness and rarity, comes close to the ideal. Opal, being relatively fragile and having little but its rarity and breathtakingly beautiful play of colors to offer, still qualifies. A number of gemstone species, such as the beautiful blue Tanzanite, have produced beautiful cut gems, but their commercial success has been sharply limited by insufficient supply—or rarity carried to an extreme. With certain notable, fashionable exceptions, a gemstone can't afford to be too rare. Scarcity does not make a stone less important as potential gem material. It merely points up the strong effect on gem marketability of the accidental, uneven, natural distribution of these species in the earth. When supply is adequate, certain attractive gems, such as spinel, still do not compete as they should with other more plentiful kinds—tourmaline, for example —that exhibit similar ornamental characteristics. Still other mineral species in adequate supply, such as fluorite and sphalerite, which are beautiful when cut and are prized by collectors, are entirely too soft, are too easily broken or cleaved, or have some other physical weakness which makes them useless as commercial gem-stones. Through a complex combination of accidents, then, certain mineral samples assume an intrinsic importance as gemstones. Continents have been explored, wars fought, crimes committed, fortunes made and lost, all in pursuit of these uncommon bits of minerals.